Small internal combustion engines often have a manually operated purge pump in fluid communication with a carburetor to allow fuel vapor and stale liquid fuel to be purged from the carburetor. The pump is generally attached directly to the carburetor, or located remotely from the carburetor. The pump is actuated by manually depressing a flexible bulb, thereby causing liquid fuel and fuel vapor within the bulb to be directed through a downstream fuel line to a fuel tank. Upon releasing the bulb, it expands to its non-deformed state, thereby drawing liquid fuel and any fuel vapor into the bulb through an upstream fuel line. Usually the bulb must be manually depressed and released 5 to 25 times to ensure that the fuel vapor is purged from the upstream fuel line. With the fuel vapor purged from the carburetor, liquid fuel generally free from fuel vapor is delivered to the engine to facilitate starting and initial operation of the engine.
Sometimes users mistake the purge pump for a priming pump and limit the number of manual actuations of the pump out of fear of “flooding” the engine. As a result, the carburetor may not be fully purged of fuel vapor prior to initiating a starting procedure for the engine, thus, making starting the engine difficult. In addition to not actuating the pump enough times, a user not familiar with the apparatus may not see the pump, or may otherwise fail to actuate the pump. As a result, it may be difficult to start and initially maintain operation of the engine.